Dental tray



Dec.11',1.923. H 1,477,098 4 L. BALTER DENTAL TRAY Filed Jan. 18. 1923 l N VENTOR ATTORN E YS I new 'LOUIS BALTEB, OF NEW YORK, N. Y.. ASSIGNOB TO BALTER; TRAY MANNFACTUEING GO INCL, OF NEW YORK, N. L, A CORPORATION OF NEW YORK.: t

DENTAL TRAY.

Application filed January 18, 1923. Serial No. 613, 323. f

This invention relates to improvements in dental trays.

It is the principal aim of the present invention to provide an improved tray for dental purposes, which shall be especially useful in taking plaster impressions for use in making upper and lower sets of artificial teeth. By the use of the present tray, various difficulties heretofore experienced will be overcome, some of which have been due either to the presence of one or more'teeth remaining in the jaw of which the impression made, with consequent adherence of the plaster to such tooth or teeth, thus occasioning much pain to the patient in attempting to remove the plastervcast in as few parts as possible to' facilitate its assembly for further use. In many instances, however, it is necessary to break the plaster cast to an objectionable. extent, and, in numerous instances, into so many parts-that accurate reassembly thereof is impossible, with the result that the whole operation has to be repeated. Even where no teeth are in the. jaw of which a plaster impression isto be made, it frequently happens thatthere are ridges on the gums, and this, of course, will occasion difficulty in removing the set plaster therefrom unless broken to an unfavorable extent with much discomfort to the patient. Briefly, the present invention comprises a tray made up of a plurality of members hinged or .pivotally .secured together, and having means positioned in the trough of the tray for weakening .orotherwise pre disposing the plaster cast to breakage on a predetermined linefwhich, in the best forms of the invention, will be on a line conforming generally to the'curvature of the teeth or gums, so that the plaster cast may be removed, in many cases, in two parts, or at least in such few parts as to make re assembly of such parts possible with accuracy. Also, due to the hinged or pivoted tray sections being so formed as to enable them to be forced apart readily on the line of the teeth or gums or both, as hereinafter explained, so as to cause breakage of the set plaster on such predetermined line, and also because such breakage "force. is applied laterally to the teeth embedded in the plas ter, or. to the gums, it will be readily seen that the patient suffers no ill effects in the operation of taking an impression for either a whole" or half plate, as'heretofore.

In order that those skilled in the art may understand my'invention, the best embodiments thereof will now betdescribedin detail, in connection with the illustration thereof in the accompanying drawings, and

the novel featuresof the invention pointed out in the claims.

In the drawings Figs. 1 and 2 are, respectively, top and bottom plan views of a lower tray embodyin my invention;

Fig.3 is a section on the line 3-8 of Fig.

then be Fig. 4; is a section of a tray taken on a similar line, but omitting the palatal arch, and showing, therefore, a lower tray in cross section with the lingual opening therein;

Fig. 5 is a sectionon the line 5-5 of'Fig. 6, and r Fig. 6 is a modified construction of tray. Fig. 7 is a section on the line 77 of Fig. l.

,eferring now to the drawings, and especiallyFigs. 'l 5, the reference letters A, B,-designate, respectively, the two-part outer tray member and the inner tray memher. The line ofseparation .between"the outer members and the inner traymember preferably conforms in shape approximately. to that of a set of teeth. On the meeting edges ofthe tray members, that is, theiinner edge of the outer members andthe outer edge of the inner member, are formed upturned rims D, thearrangement being such that when the tray members are in assembled loo.

position such ,rims'will meetand-form' a ridge conforming inshape to the meeting edges of the members, sothat plaster which has set or hardened in the tray before re-' moval from the patients mouth, will be predisposed to breakage along the line of such, ridge, and such breakage may be conveniently accomplished without pain or discomfort to the patient by inserting a flat instrument, such, for instance, as a knife blade, between the rims and prying them apart, whereupon the plaster will, in almost every instance, break only along the line of the ridge and thus enable the cast to be readily re-assembled for further use in making the plate.

The outer tray members A are preferably pivoted to the handle portion E by a pivot F arranged to positively and rigidly hold the parts in assembled position when an impressionis. to beamade, and also for keeping the trayfparts together. when not in use. The handle E and such pivot are also arranged to co-operate with an elongated wedge E, the latter being insertible in a dove-tailed, groove H formed on the bottom of the inner tray meniber,the pivot F engaging a threaded hole in such elongated wedge when the parts are in assembled-position.

The modification (Fig. 6) shows a tray for taking impressions'where noback teeth are in the jaw, such tray having saddle portions L, or portions consisting only oi": the plasterholding trough, and the 'frontal section only being provided with a ridge formed by the meeting edges or rims formed on such inner and out-er sections, so that when an impression is to be taken where only. the front teeth are present, it is only necessary to loosen the pivot F and slide back the outer member M, after the operation above described for fracturing the cast alongthe line of the partial ridge here shown is carried out.

It will'be understood that the construction and operation of both upper and lower trays is the same; except that the palatal arch N (Fig. 5) of the .upper tray here shown in cross section is dispensed with in the lower tray shown in Fig. 4, in which, of course, there is provided a lingual openng It will be understood that various changes and modifications may be made in the constructions shown while still retaining the invention defined by the claims.

, What I claim is: Q I 1. A dental'impression tray for full upper and lower jaws, comprising inner and outer tray members, a handle, a ridge in said tray conformingin shape to the line or separation of saidinner and outer tray members for. predisposing moulding material after it hardens in said tray to breakage along said line, and means cooperating with said handle and said tray members for positively and. rigidly holding the same in assembled position and permit movement of the tray members with respect to each other. 2. A dental impression tray for full upper and lower jaws, comprising outer tray members and an ,innerltray member, a handle,a ridge in said tray conforming in shape to the line of separation ofsaid inner and outer tray members for predisposing moulding material after it hardens in said tray to breakage along said line, a threaded pivot co operating with said handle and said tray members for positively and rigidly holding the latter in assembledposition" and to per mitseparation ottheouter tray members without disconnecting" saidmembers irom nor tra membenandan upturned rim onthe V inner edge or" each of said outer'tray memhere, said rims being arranged to abut and form aridge within the tray trough-of a shape approximatingthatof a set of teeth.

at. A dental impression tray, comprising outer members, an inner tray member, a handle, a wedge arranged to'cooperate with said inner tray 'member to hold the 'samein position, a pivot on said handle to which the outer tray membersare attached, an upturned rim on the outer edge or the inner tray member, and an upturned rim on the inner edge of said-outer tray'members, said rims being arranged to abut andvtorm' a ridge within the tray troughpof a shape ap proximating thatof aset otiteet'h.

5. A dental impression tray, comprising outer tray members, an inner tray member, a handle, a wedge cooperating with said inner tray member "for holding-the same in position, a'removable pivot on said handle to which said outer tray nembers are attached, an upturned rim onthe inner edge of each of the outer tray members, and an upturned rim on the outer edge of said inner tray'member, said r ms being arranged to abut and term a ridge within the tray trough, whereby plaster which 1 has hardened in said tray will be predisposed'to" breakage along the line or" said ridge.

In testimony whereof, l have hereuntov set my hand.

Louis BALTERi i 

